#include <bits/stdc++.h>

using namespace std;

#define vi vector<int>
#define ll long long
#define pb push_back
#define mp make_pair
#define ii pair<int,int>

vector<long long> sequns()
{
	vector<long long> uns(15,1);

	for (int i = 1; i < 15; ++i)
	{
		uns[i] = uns[i-1]+pow(10,i);
		//cout << "uns[i] = " << uns[i] << endl;
	}
	return uns;
}

int main(){
	long long n=0;
	vector<long long> seq;

	cin >> n;
	seq = sequns();

	int j = 1;
	for (long long i = n; i < 1e12; i+=n)
	{
		if ((seq[j] % n) == 0)
		{
			break;
		}else if(j < seq.size()-1){
		  j++;
		}
	}

	printf("%d\n",j+1);


  return 0;
}


/*
compilar
g++ arquivo.cpp -std=c++11 -o executavel
*/